It may also be comparable to the great premolar of such Multi-
tuberculata as Ptilodus and Plagiaulcux. It is, moreover, marked
with vertical grooves.
An interesting form, which is unfortunately but little known,
is the Australian and Pleistocene genus Xriclis, "with one species,
T. oseill&ns. In having a minute canine tooth in the lower jaw
it agrees with some Phalangeridae, and being otherwise closely
allied to Sypsiprymnodoii, it unites the Macropodidae with the
SUB-OHDBR 2. POLYPBOTODOSTTIA.
In this mainly carnivorous or insectivorous division of the
Marsupials the incisors are four or five on each side of the upper
Fio. 75.—Front view of the skull of Tasmanian Devil (SarcophHus ursimts), snowing
Polyprotodont and carnivorous dentition. (After Flower.)
jaw, and one or two fewer in the lower jaw. Figs. 76 and 7 7
illustrate the Polyprotodont and Diprotodont dentitions. The
canines are those of flesh-eaters and so are the molars, being as a
rule sharply cuspidate. As a rule, which has an exception in the
Peramelidae, there is no syndactylism of toes in the hind-foot.
This sub-order is at the present day Australian and American in
Fam. 1. 3>asynridae.—This family consists of Marsupials
which are generally pentadactylous, but with occasionally the
hallux missing The tail is long but not prehensile. The pouch
is present or absent. The teeth vary in the different genera, biit